We present a compact, fibre-coupled interferometer with high sensitivity and a large working range. We propose to use this interferometer as a readout mechanism for future inertial sensors, removing a major limiting noise source, and in precision positioning systems. The interferometers peak sensitivity is 2 x 10-14 m/√Hz at 70 Hz and 8 x 10-11 m/√Hz at 10 mHz. If deployed on a GS-13 geophone, the resulting inertial sensing output will be dominated by suspension thermal noise from 50 mHz to 2 Hz.
- optical interferometry
- homodyne detection